Dry Powder Inhaler

ABSTRACT

The present invention relates to a dry powder inhaler for administering a medicament via oral inhalation route to a subject. Particularly, the dry powder inhaler according to present invention is suitable for delivering accurate doses of a medicament in different ranges of inspiratory capacity of the subject.

PRIORITY DOCUMENT

This patent application claims priority to Indian Provisional PatentApplication number 4021/MUM/2013 (filed on Dec. 23, 2013), the contentsof which are incorporated by reference herein.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a dry powder inhaler for administeringa medicament via oral inhalation route to a subject. Particularly, thedry powder inhaler according to present invention is suitable fordelivering accurate doses of a medicament in different ranges ofinspiratory capacity of the subject.

BACKGROUND OF THE INVENTION

Traditionally, inhalation therapy has played a relatively minor role inthe administration of conventional pharmaceuticals compared to moreconventional drug administration routes, such as oral and intravenous.However, oral and intravenous routes have many disadvantages, andalternative administration routes are needed. Inhalation is one suchalternative administration route. Various approaches to attaininhalation type compositions are nebulizers, pressurized metered doseinhalers (pMDI) and dry powder inhalers (DPI).

A DPI has advantages over pMDIs for the delivery of inhaled drugs topediatric and geriatric patients. Many pediatric and geriatric patientshave difficulty using a pMDI correctly, because of the high speed atwhich each dose is delivered and, hence have issues following theinhalation procedure recommended in the Patient Information Leaflet. Inorder to deliver the drug effectively into the lung, the patient mustactuate the pMDI as they start to inhale. This needs a high degree of‘hand/lung’ co-ordination and failure to achieve this often results inreduced effectiveness of treatment and poor disease control. However,when using DPIs, the patient must generate sufficient inspiratory effortto ensure that the dose emitted from a DPI device contains drugparticles that have the greatest potential to be delivered to theconducting airways. The faster the inspiration rate through the DPI, thebetter is the quality of the emitted dose for lung deposition. Thisapplies to all DPIs, but for some the effect is minimal, whereas otherDPIs show significant flow-dependent dose emission, which may result inerratic dose emission and in turn compromise consistent disease control.

The variety of DPIs that are currently available come in three devicecategories: single dose inhalers in which each dose is loaded into thedevice before use; multi dose reservoir inhalers in which a bulk supplyof medicament is preloaded into the device and multiple unit-doseinhalers in which several single doses are individually sealed and asingle dose is then discharged each time the device is actuated. In thecase of multi dose inhalers, once all doses have been used the entiredevice is disposed of and a new device obtained. Nevertheless, disposingof the entire device, particularly a complex device, when empty may havecost implications, so refillable devices have been developed. For suchrefillable devices a component of the device must be replaced orrefilled when required and only the empty or no longer useable part willbe disposed of.

The DPI device which is sold by Glaxo Smith Kline under the trade nameDiskus® is one of the renowned multi-unit-dose dry powder inhalers inthe market. In Diskus DPI device, the dry powder medicament is carriedin cavities which are placed along the blister strip. The mouthpiece andlever appear by moving the mouthpiece cover to its open position. Thelever associated with the finger tab, actuates the gear mechanism as thefinger tab is slid from end to end. Hence, the blister strip isadvanced, one blister is opened, and one dose of the dry powdermedicament contained in the blister cavity, becomes ready for theinhalation.

U.S. Pat. Nos. 5,873,360, 8,161,968, 8,499,758 and 8,051,851 disclosevarious dry powder inhaler devices.

Most of the known inhaler devices have some limitations such asbulkiness, complex to assemble or non-robust structures.

There is a need for a multiple unit-dose dry powder inhaler which issimple, easy to assemble, robust to use and suitable for deliveringaccurate doses in different ranges of inspiratory capacity, easy andhygienic to use, cost effective and optionally reusable.

SUMMARY OF THE INVENTION

The present invention relates to breath-actuated dry powder inhalercomprising:

(a) dose-ring subassembly;(b) breath actuated mechanism;(c) dose opening mechanism and(d) resetting action

In an embodiment, the present invention relates to a breath-actuated drypowder inhaler, having dose-ring subassembly, said dose-ring subassemblycomprising:

(a) mouthpiece;(b) airway; and(c) dose ring;wherein said dose ring is fully enclosed in the body of a dry powderinhaler during use.

In another embodiment, the present invention relates to a reusable,breath-actuated dry powder inhaler, having dose-ring subassembly, saiddose-ring subassembly comprising:

(a) mouthpiece;(b) airway; and(c) dose ring;wherein said dose ring is fully enclosed in the body of a dry powderinhaler during use.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, having a dose opening mechanism,said mechanism comprising:

movement of the piercer blade to and fro through the lower foil, thedose pocket and the upper foil.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, having a piercer blade, said piercerblade comprising: a planar surface and protrusions or tangs whichprotrude out of the plane on either side, the piercer blade having asharp end, wherein the sharp end of piercer blade cuts a slit in thefoil, at the center of a dose pocket located on the dose ring and theprotrusions fold the foil into flaps which are pushed upwards andtowards a long side of the pocket as the piercer moves upwards.

In another embodiment, the present invention relates to a dry powderinhaler, having breath actuated mechanism (BAM), said mechanismcomprising:

(a) Priming by rotation of the mouthpiece cover through from asubstantially closed to a substantially open position;(b) Incorporation of breath induced low pressure to open the breathactuated mechanism (BAM) flap; wherein the BAM flap is held in a closedposition by a bistable biasing spring. The bistable spring is overcomeby the BAM flap moving through a breath induced pressure drop towards anopen position;(c) Furthermore during the BAM flap travel from the closed to the openposition, the movement of the BAM flap forces a latch retaining theenergized dose opening mechanism to be disengaged and triggers doseopening by the piercer blade;(d) Whereby the dose opening mechanism is energized by the opening ofthe mouthpiece cover and held in a latched position until disengaged bymovement of the BAM flap. The dose opening mechanism comprises a Shuttlethat rotates around the axis of the dry powder inhaler and furthermoreincorporates a track that guides the piercing element into and out ofthe dose container;(e) Furthermore the track comprises at least three sections: ahorizontal return track, pierce track and retract track with flexiblegates at the interfaces that force the piercing element to follow asingle route around the track;(f) Evacuation of the dry powder from dose pocket and inhalation bypatient;(g) Resetting of the BAM by closing of mouthpiece cover by a patient,wherein the priming component acting in a reverse direction to thepriming action engages with the Trigger to close the BAM flap andmoreover remains engaged with the Trigger component to prevent the BAMflap from moving;(h) During the resetting action, the priming component also acts on anindexing component which drives the dose ring to rotate and positionsthe next unopened dose pocket in line with the Airway and the Piercerready for the next inhalation.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, comprising:

(a) a body;(b) a dose-ring subassembly comprising a dose ring and an airwayincluding, airway inlets, an airway outlet, a swirl chamber and amouthpiece wherein the airway is disposed in the body and forms aconduit for bypass air and drug laden air to mix and enter the swirlchamber and wherein the swirl chamber has tangential inlets, aconvergent section, an internal post and an attenuator;(c) the dose ring fully enclosed in the body of a dry powder inhalerduring use and capable of rotating within the airway, said dose ringcomprising a plurality of sealed foil packets containing dry powdercomprising a dose of a drug,(d) a breath actuated mechanism (BAM) comprising a BAM flap movable froma substantially closed position to a substantially open position and abistable biasing spring holding the BAM flap in the substantially closedposition, the BAM being primed by rotation of the mouthpiece cover fromthe substantially fully closed to the substantially fully open positionsuch that breath induced low pressure opens the BAM flap and thebistable biasing spring is overcome by the BAM flap moving through abreath induced pressure drop towards the substantially open position;(e) a piercer blade comprising a planar surface and tangs which protrudeout of the plane on either side,wherein during the BAM flap travel from the closed to the open position,the movement of the BAM flap forces a latch retaining the energized doseopening mechanism to be disengaged and triggers a dose opening by thepiercer blade, and wherein the dose opening mechanism is energized bythe opening of the mouthpiece cover and held in a latched position untildisengaged by movement of the BAM flap, the piercer blade having a sharpend which cuts a slit in the foil, at the center of a dose pocketlocated on the dose ring, the tangs folding the foil into flaps whichare pushed upwards and towards a long side of the pocket as the piercermoves upwards, such that the piercer blade moves through the lower foil,the dose pocket and the upper foil, such that evacuation of the drypowder from the dose pocket is initiated by inhalation by a patientthrough the mouthpiece.

In another embodiment, the present invention relates to a reusable,breath-actuated dry powder inhaler, comprising:

(a) a body;(b) a dose-ring subassembly comprising a dose ring and an airwayincluding airway inlets, an airway outlet, a swirl chamber and amouthpiece wherein the airway is airway disposed in the body and forms aconduit for bypass air and drug laden air to mix and enter a swirlchamber and wherein the swirl chamber has tangential inlets, aconvergent section, an internal post and an attenuator;(c) the dose ring fully enclosed in the body of a dry powder inhalerduring use and capable of rotating within the airway, said dose ringcomprising sealed foil packets containing dry powder comprising a doseof a drug,(d) a breath actuated mechanism (BAM) comprising a BAM flap movable froma substantially closed position to a substantially open position and abistable biasing spring holding the BAM flap in the substantially closedposition, the BAM being primed by rotation of the mouthpiece cover fromthe substantially fully closed to the substantially fully open positionsuch that breath induced low pressure opens the BAM flap and thebistable biasing spring is overcome by the flap moving through a breathinduced pressure drop towards the substantially open position;(e) a piercer blade comprising a planar surface and tangs which protrudeout of the plane on either side,wherein during the BAM flap travel from the closed to the open position,the movement of the BAM flap forces a latch retaining the energized doseopening mechanism to be disengaged and triggers dose opening by thepiercer blade, and the dose opening mechanism is energized by theopening of the mouthpiece cover and held in a latched position untildisengaged by movement of the BAM flap, the piercer blade having a sharpend which cuts a slit in the foil, at the center of a dose pocketlocated on the dose ring, the tangs folding the foil into flaps whichare pushed upwards and towards a long side of the pocket as the piercermoves upwards, wherein the piercer blade moves through the lower foil,the dose pocket and the upper foil, such that evacuation of the drypowder from the dose pocket is initiated by inhalation by a patientthrough the mouthpiece.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, comprising:

(a) a body;(b) a dose-ring subassembly comprising a dose ring and an airwayincluding a swirl chamber and a mouthpiece, wherein the airway hasairway inlets and an airway outlet, said airway forming a conduit forbypass air and drug laden air to mix and enter the swirl chamber,and wherein the dose ring is fully enclosed in the body of the drypowder inhaler during use and is capable of rotating through a segmentof the airway, said dose ring comprising a plurality of sealed foilpackets, with each packet containing dry powder comprising a dose of adrug,(c) a breath actuated mechanism (BAM) comprising a BAM flap movable froma substantially closed position to a substantially open position and abistable biasing spring holding the BAM flap in the substantially closedposition, the BAM being primed by rotation of a mouthpiece cover from asubstantially closed to a substantially open position such that breathinduced low pressure overcomes the bistable biasing spring to allowopening of the BAM flap wherein the bistable spring acts to move the BAMflap to the open, and(d) a piercer blade;wherein during the BAM flap travel from the closed to the open position,the movement of the BAM flap forces a latch retaining an energized doseopening mechanism to be disengaged, thereby triggering dose opening bythe piercer blade, wherein the dose opening mechanism is energized bythe opening of the mouthpiece cover and is held in a latched positionuntil disengaged by movement of the BAM flap and further wherein thepiercer blade which cuts a slit in the sealed foil packet, of a dosepocket located on a dose ring, the tangs folding the foil into flapswhich are pushed upwards and towards a long side of the dose pocket asthe piercer moves upwards, such that the piercer blade moves through alower foil, the dose pocket and an upper foil.

In yet another embodiment, the present invention relates to a method ofindicating the inhalation dosage dispensed from a dry powder inhalerthrough emission of an audible signal, the method comprising:

(a) opening of a lever or a mouthpiece cap of said inhaler to prime abreath activated mechanism (BAM) by rotation of the lever or themouthpiece cover from a substantially closed to a substantially openposition;(b) successively moving a BAM flap from a substantially closed positionto a substantially open position, wherein a bistable biasing springholds the BAM flap in the substantially closed position until thebistable biasing spring is overcome by a breath induced low pressure toallow opening of the BAM flap; and(c) wherein an audible signal is emitted upon movement of the BAM flapto said open position.

In another embodiment, the present invention also relates to a method ofactivating a breath actuated mechanism (BAM) of a dry powder inhaler,wherein said method comprises the following steps:

(a) priming a breath actuated mechanism (BAM) by rotation of amouthpiece cover through from a substantially closed to a substantiallyopen position, wherein opening the mouthpiece cover energizes a doseopening mechanism and holds the dose opening mechanism in a latchedposition until disengaged by movement of a BAM flap, wherein the doseopening mechanism comprises a shuttle that rotates around an axis of thedry powder inhaler and furthermore incorporates a track that guides apiercing element comprising a piercer blade into and out of a dosepocket of a dose container;(b) incorporation of a breath induced low pressure to open the BAM flap;wherein the BAM flap is held in a closed position by a bistable biasingspring and wherein the bistable biasing spring is overcome by the BAMflap moving through the breath induced pressure drop towards an openposition and further wherein the bistable biasing spring acts to movethe BAM flap to the open position;(c) moving the BAM flap during the travel of the BAM flap from theclosed to the open position to force a latch retaining an energized doseopening mechanism to be disengaged and triggering opening by the piercerblade of the dose pocket of the dose container which contains a drypowder;(d) forcing the piercing element to follow a single route around thetrack, wherein the track comprises at least: a horizontal return track,a pierce track and a retract track with flexible gates at interfacesthat force the piercing element to follow the single route around thetrack;(e) evacuating the dry powder from the dose pocket upon inhalation by apatient; and(f) resetting the dry powder inhaler by closing of the mouthpiece coverby the patient, wherein a priming component which acts in a reversedirection to the priming action is engaged with a trigger to close theBAM flap and remains engaged with the trigger to prevent the BAM flapfrom moving,wherein the dose container is a dose ring and wherein the primingcomponent also acts on an indexing component which drives the dose ringto rotate and positions the next unopened dose pocket in line with anairway and the piercing element to be ready for evacuation of the drypowder from the dose pocket upon the next inhalation.

In a further aspect, after the opening of a lever or a mouthpiece cap ofsaid inhaler, the successively moving of BAM flap from a substantiallyclosed position to a substantially open position results in emission ofan audible signal. In other embodiment the audible signal can be emittedby movement of the bistable biasing spring or by a combination of themovement of the BAM flap and the bistable biasing spring. In yet furtherembodiment audible signal can be emitted by movement of piercer bladewhile cutting a slit in the foil or by a combination of the movement ofBAM flap and piercer blade which cuts a slit in the foil.

In yet another embodiment, the present invention relates to abreath-actuated dry powder inhaler, comprising: a breath actuatedmechanism (BAM) comprising a BAM flap movable from a substantiallyclosed position to a substantially open position and a bistable biasingspring holding the BAM flap in the substantially. closed position, theBAM being primed by rotation of a lever or a mouthpiece cover from asubstantially closed to a substantially open position such that breathinduced low pressure overcomes the bistable biasing spring to allowopening of the BAM flap wherein the bistable spring acts to move the BAMflap to the open position resulting in a push of air to sweep through adose pocket. In a further aspect, prior to the movement of air throughthe dose pocket, the dose pocket has been opened. In certain preferredembodiments a slit in the dose pocket is made by e.g. a piercingelement. In certain other embodiments the dose pocket is slit by apiercer blade after which tangs which protrude out of the plane oneither side of the piercer blade fold the foil into flaps which arepushed upwards and towards a long side of the pocket as the piercermoves upwards.

In another embodiment, the piercer blade may be of spiral shape ortriangular shape. In another embodiment, the piercer may have more thanone blade. In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, wherein the dose opening mechanismcomprises a shuttle that rotates around the axis of the dry powderinhaler and furthermore incorporates a track that guides the piercingelement in to and out of the dose container, wherein the track comprisesat least three sections: a horizontal track, pierce track and retracttrack with flexible gates at the interfaces that force the piercingelement to follow a single route around the track.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, wherein during the resetting action,the priming component also acts on an indexing component which drivesthe dose ring to rotate and positions the next unopened dose pocket inline with the Airway and the Piercer ready for the next inhalation.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, which is reset by closing of themouthpiece cover by a patient, wherein the priming component acting in areverse direction to the priming action engages with a Trigger to closethe BAM flap and moreover remains engaged with the Trigger to preventthe BAM flap from moving.

In another embodiment, the present invention relates to abreath-actuated dry powder inhaler, which incorporates a breath holdtimer which is activated by the patient inhalation and provides anaudible alarm for a fixed time after inhalation has begun to encouragethe patient to hold their breath.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the invention can be better understood with reference tothe following drawings. The components in the drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present invention. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1: Internal exploded view of dry powder inhaler device;

FIG. 2: Air passage route between Dose Ring and Mouthpiece;

FIG. 3: BAM—Top View;

FIG. 4: BAM—Bottom View;

FIG. 5: Piercer—Side on view;

FIG. 6: Piercer Blade—Prospective View;

FIG. 7: Inlets to Flap Chamber and Swirl Chamber-Top View;

FIG. 8: Airpath from Flap Chamber inlets to swirl chamber—when Flap isfully open-Top Transparent View;

FIG. 9: Priming Arm—Top Prospective View;

FIG. 10(a): Shuttle-Top Prospective View;

FIG. 10(b): Shuttle (Reverse)—Bottom Prospective View;

FIG. 11: Indexing Arm—Top Prospective View;

FIG. 12(a): Device Primed;

FIG. 12(b): Indexer Primed;

FIG. 12(c): Indexing;

FIG. 12(d): Device Reset;

FIG. 13: Shuttle Tracks—Longitudinal Cross-sectional View;

FIG. 14: Chassis-Top View;

FIG. 15: Dose Ring/Airway Subassembly-Top Transparent View;

FIG. 16(a): Breath actuated mechanism: BAM flap closed;

FIG. 16(b): Breath actuated mechanism: balance point;

FIG. 16(c): Breath actuated mechanism: push off point;

FIG. 16(d): Breath actuated mechanism: triggered;

FIG. 17(a): Airway Components-Side Prospective View;

FIG. 17(b): Cross Section of Airway-Longitudinal Cross-Sectional View;

FIG. 18: Airflow through Swirl Chamber: Front View;

FIG. 19: Airflow through Swirl Chamber: Side View;

The Figures only represent embodiments of the present invention. Theembodiments are meant only for the purpose of illustration of thepresent invention. Different parts of the device of these embodimentsare labelled in FIGS. 1 to 19 and the labelling is described in theschedule of the reference numerals herein below.

Schedule of reference numerals 1: Chassis 2: Indexing Arm 3: Piercer 4:Shuttle Inner 5: Shuttle Outer 6: Drive Spring 7: Priming Arm 8: Trigger9: Idler Gear 10: Biasing Spring 11: BAM Flap 12: Chassis Lid 13: DoseRing 14: Airway Inlet 14A: Clean Air Inlet 14B: Drug Laden Air Inlet 15:Airway Outlet 16: Shuttle (made up of Shuttle Inner [4] and ShuttleOuter [5]) 17. Mouthpiece Cover 18. Indexing Cam Follower (on IndexingArm) 19. Pawl Arm (on Indexing Arm) 20. Flexible Clip (on Priming Arm)21. Trigger Arm (on Shuttle) 22. Cut outs for Air Flow (on Piercer) 23.Piercer Carriage (on Piercer) 24. Cam Follower Pegs (on Piercer) 25.Tangs (on Piercer) 26. Mouthpiece 27. Flap Chamber Air Inlets 28.Piercer Blade (on Piercer) 29. Indexing Foot (on Priming Arm) 30. DriveLug (on Shuttle) 31. Dose Ring Clip 32. Magnifying Lens 33. UpperClamshell 34. Lower Clamshell 35. Blanking Plate 36. Pierce Track (onshuttle) 37. Retract Track (on shuttle) 38. Return Track (on shuttle)39. Stop (on chassis) 40. Indexing Cam Track (on shuttle) 41. BAM FlapAxle 42. Dose Ring Tooth Driving Surface/Drive Teeth 43. Dose Pocket 44.BAM Cavity 45. Mouthpiece Cover Gear 46. Ratchet Arm 47. Pierce Gate Arm48. Dose Ring Latch 49. Dose Ring Notch 50. Mouthpiece Cover Detent Arm51. Return Gate Arm 52. Trigger Arm Notch 53. Chassis Lid Inlet Holes54. Swirl Attenuator/Mesh 55. Central Post 56. Swirl Chamber 57.Convergent Section

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a dry powder inhaler device which isused for administering medicament via oral inhalation route. The devicecontains a breath actuated mechanism (BAM). This BAM causes the dosepocket to be opened and the powder evacuated when the user inhales atthe correct flow rate. The BAM is primed (charged) by the user openingthe mouthpiece cover.

With regards to fastening, mounting, attaching or connecting componentsof the present invention, unless specifically described as otherwise,conventional mechanical fasteners and methods may be used. Otherappropriate fastening, or attachment methods include adhesives, welding,including ultra-sonic welding, or soldering. Generally, unless otherwiseindicated, the materials for making embodiments of the invention and/orcomponents thereof may be selected from appropriate material such asmetal, metallic alloys, ceramics, plastic etc. Unless stated otherwisepositional terms e.g., Top, Bottom, Front, Side, Rear, Distal, Proximaletc. are descriptive and not meant to be limiting

In an embodiment, the present invention relates to a breath-actuated drypowder inhaler, comprising:

(a) a body;(b) a dose-ring subassembly comprising a dose ring and an airwayincluding a swirl chamber and a mouthpiece, wherein the airway hasairway inlets and an airway outlet, said airway forming a conduit forbypass air and drug laden air to mix and enter the swirl chamber,and wherein the dose ring is fully enclosed in the body of the drypowder inhaler during use and is capable of rotating through a segmentof the airway, said dose ring comprising a plurality of sealed foilpackets, with each packet containing dry powder comprising a dose of adrug,(c) a breath actuated mechanism (BAM) comprising a BAM flap movable froma substantially closed position to a substantially open position and abistable biasing spring holding the BAM flap in the substantially closedposition, the BAM being primed by rotation of a mouthpiece cover from asubstantially closed to a substantially open position such that breathinduced low pressure overcomes the bistable biasing spring to allowopening of the BAM flap wherein the bistable spring acts to move the BAMflap to the open, and(d) a piercer blade;wherein during the BAM flap travel from the closed to the open position,the movement of the BAM flap forces a latch retaining an energized doseopening mechanism to be disengaged, thereby triggering dose opening bythe piercer blade, wherein the dose opening mechanism is energized bythe opening of the mouthpiece cover and is held in a latched positionuntil disengaged by movement of the BAM flap and further wherein thepiercer blade which cuts a slit in the sealed foil packet, of a dosepocket located on a dose ring, the tangs folding the foil into flapswhich are pushed upwards and towards a long side of the dose pocket asthe piercer moves upwards, such that the piercer blade moves through alower foil, the dose pocket and an upper foil.

In yet another embodiment, the present invention relates to a method ofindicating the inhalation dosage dispensed from a dry powder inhalerthrough emission of an audible signal, the method comprising:

(a) opening of a lever or a mouthpiece cap of said inhaler to prime abreath activated mechanism (BAM) by rotation of the lever or themouthpiece cover from a substantially closed to a substantially openposition;(b) successively moving a BAM flap from a substantially closed positionto a substantially open position, wherein a bistable biasing springholds the BAM flap in the substantially closed position until thebistable biasing spring is overcome by a breath induced low pressure toallow opening of the BAM flap; and(c) wherein an audible signal is emitted upon movement of the BAM flapto said open position.

In another embodiment, the present invention also relates to a method ofactivating a breath actuated mechanism (BAM) of a dry powder inhaler,wherein said method comprises the following steps:

(a) priming a breath actuated mechanism (BAM) by rotation of amouthpiece cover through from a substantially closed to a substantiallyopen position, wherein opening the mouthpiece cover energizes a doseopening mechanism and holds the dose opening mechanism in a latchedposition until disengaged by movement of a BAM flap, wherein the doseopening mechanism comprises a shuttle that rotates around an axis of thedry powder inhaler and furthermore incorporates a track that guides apiercing element comprising a piercer blade into and out of a dosepocket of a dose container;(b) incorporation of a breath induced low pressure to open the BAM flap;wherein the BAM flap is held in a closed position by a bistable biasingspring and wherein the bistable biasing spring is overcome by the BAMflap moving through the breath induced pressure drop towards an openposition and further wherein the bistable biasing spring acts to movethe BAM flap to the open position;(c) moving the BAM flap during the travel of the BAM flap from theclosed to the open position to force a latch retaining an energized doseopening mechanism to be disengaged and triggering opening by the piercerblade of the dose pocket of the dose container which contains a drypowder;(d) forcing the piercing element to follow a single route around thetrack, wherein the track comprises at least: a horizontal return track,a pierce track and a retract track with flexible gates at interfacesthat force the piercing element to follow the single route around thetrack;(e) evacuating the dry powder from the dose pocket upon inhalation by apatient; and(f) resetting the dry powder inhaler by closing of the mouthpiece coverby the patient, wherein a priming component which acts in a reversedirection to the priming action is engaged with a trigger to close theBAM flap and remains engaged with the trigger to prevent the BAM flapfrom moving,wherein the dose container is a dose ring and wherein the primingcomponent also acts on an indexing component which drives the dose ringto rotate and positions the next unopened dose pocket in line with anairway and the piercing element to be ready for evacuation of the drypowder from the dose pocket upon the next inhalation.

An embodiment of the dry powder inhaler device of the invention in shownin FIGS. 1 to 19 and is described below. A schematic exploded view ofthe dry powder inhaler device is shown in FIG. 1 and components arementioned in above table.

As seen in FIGS. 3 and 4, the rotation of the Mouthpiece Cover (17)directly or indirectly winds a priming torsion spring, the Drive Spring(6), by rotation of one end of the Spring attached to the Priming Arm(7). The other end of the Spring is attached to the Shuttle (16) whichis prevented from rotating by the Trigger Arm (21) latching against theStop (39) which is visible in FIG. 14 on the Chassis. When a pressuredrop is produced by the patient inhaling, the Shuttle (16) is free torotate. Once the BAM is primed, the dose can be released as the userinhales at the desired flow rate. As the inhaled air flows towards theBAM Flap (11), the pressure drop causes the flap to rotate and theTrigger Arm (21), which is coupled to the BAM Flap Axle (41), rotatesabout the vertical axis to move a latch feature (the Trigger Arm (21) ofthe Shuttle (16)), thereby releasing the Shuttle (16) to rotate, drivenby the Drive Spring (6), which may be, e.g., a torsion spring.

As seen in e.g. FIGS. 12(a)-(d), once the BAM has been triggered, thedose ring indexing mechanism is primed. The Shuttle Inner (4) has anIndexing Cam Track (40) that, as it moves pushes against an Indexing Cam(2) Follower (18) on the Indexing Arm causing the Indexing Arm (2) torotate. The Pawl Arm (19) on the Indexing Arm (2) flexes and bumps overone of the drive teeth on the Dose Ring (13). The tip of the Pawl Arm(19) is now in position to push against a Dose Ring Driving Surface (42)during indexing. After this movement the Dose Ring (13) is preventedfrom rotating backwards, e.g., by the positioning ratchet teeth on theChassis (1). This means that as the mouthpiece cover is closed, the DoseRing (13) will be indexed by one count so that an unopened dose sitsdirectly above the Piercer (3).

The other components of the dry powder inhaler device of the presentinvention are as below:

Dose Ring

The dose ring is circular in shape and has space for a plurality of dosepackets. In one preferred embodiment, the dose ring has 61 dose pockets,of which 60 are filled. The 61st space is empty and provided as a blankstation. The 61st position allows for an “empty” or “0” indicator to beprinted on the foil, which will appear once the final dose is taken andindexed on.

The number of remaining doses is printed on the foil and viewed througha Magnifying Lens (32), which forms part of the device.

The Airway clips on to the Dose Ring (13) via the Dose Ring Clip (31)and offers protection to the foil during handling by the user.

Airway

The airway and Mouthpiece (26) form part of the dose ring subassembly.In certain embodiments, the airway is comprised of one or more inlets,one or more airway outlets and a swirl chamber. In certain embodimentsthe mouthpiece is also part of the airway. The primary purpose of theairway is to form a conduit for bypass air and drug laden air to mix andenter a swirl chamber. The swirl chamber (56) acts to impart energy intothe drug laden air and de-agglomerate the fine particles from thelactose carrier particles in the powder formulation.

Dose Ring Subassembly

The Dose Ring Subassembly is made up of a filled and sealed Dose Ring(13) which, in certain embodiments, is permanently fixed to a mouldedairway and mouthpiece assembly. In alternative embodiments, the DoseRing is removably attached to the airway and mouthpiece assembly. Theassembly between the dose ring and the airway allows the free rotationof the dose ring relative to the airway when the assembly is insertedinto the device. In such embodiments, the Airway is made up of an AirwayInlet (14) and Airway Outlet (15) components. The Airway Inlet (14)clips to the Dose Ring Clip (31) around the Dose Ring (13). In otherembodiments, the Airway and Dose Ring Clip (31) may be formed as asingle component.

FIG. 2 shows a dose-ring subassembly comprising Dose Ring (13), AirwayInlets (14), Airway Outlet (15) and the Mouthpiece. FIG. 2 also showsair passage route between Dose Ring (13) and Mouthpiece (26).

FIGS. 3 and 4 show the front view and back view of components related tothe Breath Actuated Mechanism of the Dry Powder Inhaler. The DriveSpring (6) is a torsion spring, the arms of which are constrained by thePriming Arm (7) and a feature on the Shuttle (16). This Drive Spring (6)is energised as the Mouthpiece Cover (17) is opened. The rotation of theMouthpiece Cover (17) drives the Idler Gear (9) which, in turn, drivesthe Priming Arm (7). The Shuttle (16) is prevented from rotating by theTrigger Arm (21) feature of the Shuttle (16) being engaged with a Stop(39) on the underside of the Chassis (1). The Trigger Arm (21) isnaturally biased towards the position of the Stop (39) and flexes whenthe Trigger (8) rotates and pushes against the end of the Trigger Arm(21). In an alternative embodiment, the Trigger Arm (21) may be aseparate component which pivots about an axle which is constrained in ahole through the Shuttle (16). The breath actuated mechanism is a ‘pushoff’ design, whereby the Trigger Arm (21) is released from its latchedposition by a feature on the Trigger (8) pushing against the Trigger Arm(21) as the BAM Flap (11) rotates about its axle (41).

FIGS. 5 and 6 show the Piercer (3) as a single molded plastic component.A Metal blade is an integral part of the Piercer (3) or can be aseparate part which is irremovably attached to the Piercer (3). In analternative embodiment, the Piercer can be formed as a metal bladeassembled into a plastic carriage. In an embodiment, the Piercer (3) isa flat blade (28) with Tang (25) features which protrude out of theplane on either side of the Piercer (3). The sharp end of the Piercer(3) cuts a slit in the foil, at the center of the Dose Pocket (43). Asthe Piercer (3) moves upwards, the Tangs (25) fold the foil in to flapswhich are pushed upwards and towards the long side of the dose pocket.The Piercer Blade (28) is mounted in to a Piercer Carriage (supportblock) (23). In certain embodiments, the Piercer Carriage has CamFollower Pegs (24) on opposite sides, which allow it to be drivenvertically by the Cam Track (see 36, 37 and 38 in FIG. 13) of theShuttle (16). The Piercer (3) is guided by a guide feature on theunderside of the Chassis (1).

FIGS. 7 and 8 show the evacuation of the powder dose chamber to themouthpiece. At the beginning of BAM Flap (11) rotation, the BAM Flap(11) is positioned within a close fitting portion of the BAM cavity(44). Air flow into the Airway (14) is preferably highly restricted toonly leaks. When the BAM Flap (11) has rotated through approximately 24degrees, it reaches the open section of the BAM cavity (44). Thisposition allows air to flow more freely around the short end of the BAMFlap (11) (and into the two inlet tubes (14A and 14B)) leading to theSwirl Chamber (56). Initiation of free flow into and through the SwirlChamber (56) is intended to be largely simultaneous with piercing of thedose pocket. Ideally, flow will be established through the two air inlettubes just prior to piercing so that the dose pocket flow encounters theperpendicular air flow through the inlet. The tension in the BiasingSpring (10) keeps the BAM Flap (11) in its open position throughout theinhalation. Evacuation of the dose pocket should be achieved within onefull inhalation.

FIG. 9 shows Priming Arm (7) comprising Flexible Clip (20) and IndexingFoot (29). FIG. 10a shows Shuttle (16) comprising Trigger Arm (21),Drive Lug (30) and Indexing Cam Track (40). FIG. 10b shows the reversepart of Shuttle (16) comprising Trigger Arm Notch (52). FIG. 11 showsIndexing Arm (2) comprising Indexing Cam Follower (18) and Pawl Arm(19).

FIGS. 12(a)-12(d) shows the Dose Ring indexing mechanism. Once the BAMhas fired, the Dose Ring (13) will be indexed by one dose as theMouthpiece Cover (17) is rotated to a closed position. As the MouthpieceCover (17) is rotated, the mouthpiece Cover Gear (45) on the axle of themouthpiece Cover (17) drives the Idler Gear (9), which in turn drivesthe Priming Arm (7). The Drive Spring (6) rotates (in its de-energisedstate) with the Shuttle (16), which is rotated back to its startposition by the Flexible Clip (20) on the Priming Arm (7) which pushesagainst the Drive Lug (30) on the Shuttle (16).

As seen in FIG. 12 (c), the Priming Arm (7) rotates, the Indexing Foot(29) feature on the Priming Arm (7) drives the Indexing Cam Follower(18) on the Indexing Arm (2), causing the Indexing Arm (2) to rotateabout its axle. The tip of the Flexible Pawl Arm (19) pushes against theback of the Saw Tooth (42) on the Dose Ring (13) and causes the DoseRing (13) to advance by one dose. As the Dose Ring (13) moves, thepositioning Ratchet Arm (46) on the Chassis (1) flexes and allows theDose Ring Tooth to pass. The Dose Ring (13) is prevented from rotatingbackwards by the positioning Ratchet Arm (46) (shown in FIG. 14)returning to an unstressed position and the Ratchet Teeth restingbetween Drive Teeth (42) on the Dose Ring (13).

As the Shuttle (16) rotates, the Cam Follower Pegs (24) on the PiercerCarriage (23) travel along the Return Track (38) and the Pierce GateArms (47) are flexed outwards and the Cam Follower Pegs (24) passthrough this gate.

As the Shuttle (16) rotates, the Trigger Arm (21) is biased towards theStop (39) on the Chassis (1). When the Trigger Arm Notch (52) in theTrigger Arm (21) reaches the Stop (39) feature on the Chassis (1), theTrigger Arm (21) engages, preventing the Shuttle (16) from rotatingclockwise (viewed from below) until it is re-primed and re-triggered.

The BAM Flap (11) is also reset to the closed position by the closure ofthe Mouthpiece Cover (17). A curved wall on the Priming Arm (7)interfaces with a profiled wall on the Trigger (8) so that as thePriming Arm (7) rotates, the Trigger (8) (and therefore the BAM FlapAxle (41)) is forced to rotate. Once the Mouthpiece Cover (17) is fullyclosed, the location of the curved wall on the Priming Arm (7) next tothe profiled wall on the Trigger (8) prevents the BAM Flap (11) fromrotating.

In one alternate embodiment, the inhaler device may contains, aMouthpiece Cap (17) and a lever, wherein the opening and closing of thelever is responsible for successive movement of BAM Flap (11).

FIG. 13 shows Shuttle Tracks comprising Pierce Track (36), Retract Track(37), Return Track (38), Pierce Gate Arms (47) and Return Gate (51).FIG. 14 shows Chassis (1) comprising Stop (39), Ratchet Arm (46) andMouthpiece Cover Detent Arm. FIG. 15 shows Dose Ring Subassemblycomprising Dose Ring Latch (48), Dose Ring Notch (49) and Dose Ring Clip(31). FIGS. 16 (a)-(d) show the Breath Actuated Mechanism comprising BAMFlap (11), Clean Air Inlet (14A), Drug Laden Air Inlet (14B), BAM FlapAxle (41), Bistable Biasing Spring (10) and Chassis Lid Inlet Holes(53). Specifically, FIG. 16(a) shows the breath actuated mechanism withthe BAM flap closed; FIG. 16(b) shows the breath actuated mechanism atthe balance point, FIG. 16(c) shows the breath actuated mechanism at thepush off point and FIG. 16(d) shows the breath actuated mechanism afterit is triggered. FIG. 17 (a-b) shows Airway Components comprising CleanAir Inlet (14A), Drug Laden Air Inlet (14B), Swirl Attenuator/Mesh (54)and Central Post (55) with FIG. 17(b) showing the airway in a crosssection view. FIGS. 18 and 19 shows air flow through swirl chamber. Itshows that air enters through Clean Air inlet (14A) and Drug Laden AirInlet (14B), further moves in Swirl Chamber (56) and finally comes outthrough Mouth Piece (26).

The general working of the dry powder inhaler device of the invention isgiven below:

Loading of Dose-Ring Subassembly:

In one embodiment, the present invention relates to a dry powder Inhalerdevice which is designed to be reusable with the replacement of asubassembly comprising the primary dose container and airway, the“Dose-Ring Subassembly”. The Dose-Ring Subassembly prevents the DoseRing (13) from being rotated until it is fully assembled into the wholedevice. This prevents the user from accidentally or deliberatelyrotating the Dose Ring (13) to either waste dose or reverse the DoseRing (13) to reuse used doses.

This can be achieved via a Dose Ring Latch (48) on the Dose Ring Clip(20) which engages with one of 61 Dose Ring Notches (49) on the DoseRing (13). If the Upper Clamshell (33) is opened at any point during theDose Ring life, this latch will engage and prevent the Dose Ring (13)from being rotated. In alternative embodiments, this Dose Ring Latch canbe located on the Airway.

The User (e.g., a human patient) opens the Mouthpiece Cover (17) fullythrough, e.g., approximately 100-120 degrees. The Mouthpiece Cover (17)is held open at the extreme of travel by a detent feature. The detentfeature itself consists of a Mouthpiece Cover Detent Arm (50) integralto the Chassis (1) (shown in FIG. 14). The inherent strength of the armprovides sufficient force to resist the Mouthpiece Cover (17) closing.Alternatively, the arm may be loaded by a spring to provide this force.If the user releases the Mouthpiece Cover (17) during opening prior toreaching the detent, the Mouthpiece Cover (17) will tend to close byitself. The detent feature also acts to secure the Mouthpiece Cover (17)in the closed position in addition to the base-line closing torqueprovided by the Drive Spring's (6) pre-load.

The user depresses tab features on the Upper Clamshell (33) whichunlatches the Upper Clamshell (33). These tab features may be depressedat any time during the Dose Ring use life, i.e. the user can open theClamshell at any time.

In certain embodiments, once open, the user may open the Upper Clamshell(33) sufficiently to access the inside of the device. The device is nowready to accept a new Dose Ring Subassembly.

In a single use variant, the Clamshell release tabs will not be presentor will be deactivated and the Clamshells will be permanently lockedtogether. The Upper Clamshell may only be closed if the Dose RingSubassembly has been inserted in the correct orientation (dose numbersvisible once inserted). The Mouthpiece/Airway fits into the recess inthe Chassis. Leaf spring features on top of the Airway maintain the sealbetween Chassis, Dose Ring & Airway. Airway guide features on the UpperClamshell interact with pips on the Airway, pushing the Airway inletchannels against the central Flap chamber as the Upper Clamshell isclosed.

As the Dose Ring Subassembly is inserted, the Dose Ring drive teethpreferably are aligned with the positioning ratchet teeth on theChassis.

When Mouthpiece Cover is Opened:

Priming of the breath actuated mechanism (BAM) is achieved throughrotation of the Mouthpiece Cover (17) through, e.g., approximately100-120 degrees from a fully closed to a fully open position.

The BAM Flap (11) is held in a closed position by the Bistable BiasingSpring (10), which in certain embodiments is a flat spring, mounted intothe Chassis (1). The free end of the Bistable Biasing Spring (10) restsin contact with a cam surface on the Trigger (8). In an alternativeembodiment, the Bistable Biasing Spring (10) is an extension spring; oneend of which is attached to the Trigger (8), the other end of theBistable Biasing Spring (10) is attached to the Priming Arm (7).

With reference to FIG. 3, the Drive Spring (6) is preferably a torsionspring, the respective ends of which are constrained by the Priming Arm(7) and a feature on the Shuttle (16). This Drive Spring (6) isenergised as the Mouthpiece Cover (17) is opened. The rotation of theMouthpiece Cover (17) drives the Idler Gear (9) which, in turn, drivesthe Priming Arm (7). The Shuttle (16) is prevented from rotating by theTrigger Arm (21) being engaged with the Stop (39) located on theunderside of the Chassis. The Trigger Arm (21) is naturally biasedtowards the stop position so that the Shuttle (16) is unable to rotate.

When the User Inhales Through the Mouthpiece:

The breath actuated mechanism is preferably a ‘push off’ design, wherebythe Trigger Arm (21) is released from its latched position by a featureon the Trigger (8) pushing against the Trigger Arm (21) as the BAM Flap(11) rotates about its axle.

As the user inhales through the Mouthpiece (26), a partial vacuum iscreated behind the BAM Flap (11) in its closed position; air is drawn into the device through the air inlets (14) and (14A). This air flowtravels through the Chassis Lid Inlet Holes (53) towards the upstreamside of the BAM Flap (11). The pressure drop created between the BAMFlap (11) and the Mouthpiece (26) develops a moment arm around the BAMFlap Axle. This moment arm must overcome the force from the BistableBiasing Spring (10) and frictional forces on the BAM Flap (11) beforethe BAM Flap (11) starts to rotate towards the Mouthpiece (26). Duringthe first (approximately) 5 degrees of movement, the Bistable BiasingSpring (10) is flexed to a maximum deflection with zero moment armlength (the Trigger (8) is perpendicular to the Bistable Biasing Spring(10)) and therefore no torque. This is the balance point. Beyond thebalance point, the Bistable Biasing Spring (10) acts to open the BAMFlap (11) rather than restore it to the closed position. As the usercontinues to inhale, the BAM Flap (11) moves past the balance point,which, due to the presence of friction is actually an angular rangerather than a specific point, and the Bistable Biasing Spring (10)begins to flex back towards its rest position. The moment arm at whichit acts increases so that the net result is an increase in openingtorque as the BAM Flap (11) rotates. This means that as soon as thebalance point is passed, the BAM Flap (11) will preferably trip rapidlyto the fully open position independently of user-applied pressure,opening of the BAM Flap (11) results in the push of a pocket of airtowards the air inlets through the Dose Pockets (43). The flow of air asit sweeps through the Dose Pocket (43) varies with the dimensions of theBAM Flap (11), the length of Bam Flap Axle, the tension created by theBistable Biasing Spring (10), the location of BAM Flap (11) and the BamFlap angle of defection. These help in improving the performance of theinhalation device. In certain embodiments, the movement of the Bam Flap(11) results in emission of an audible signal which indicates the end ofthe inhalation dose. It is possible to change the audible signal, aswould be understood by one of skill in the art, by altering thedimensions of the BAM Flap (11), the length of Bam Flap Axle, thetension created by Bistable Biasing Spring (10), the position of BAMFlap (11), the Bam Flap angle of defection and/or the material ofconstruction of the BAM Flap (11) and parts which comes in contact atthe time of tripping.

In certain embodiments, the opening of a lever or a mouthpiece cap ofthe inhaler, the successive movement of the BAM Flap (11) from asubstantially closed position to a substantially open position and theemission of the audible signal indicate the start of the inhalationdose.

At e.g., approximately 17 degrees of BAM Flap (11) movement, the Trigger(8) engages with the Trigger Arm (21). As the BAM Flap (11) movesthrough a further approximately 11 degrees, the push off feature on theTrigger (8) forces the Trigger Arm (21) to unlatch from the stop on theChassis (1).

The rotating Shuttle (16) described above as part of the Breath ActuatedMechanism also preferably drives the piercing function. With the TriggerArm (21) disengaged from the stop, the Drive Spring (6) is able tode-energise, driving the Shuttle (16) to rotate in a clockwisedirection.

The rotation of the Shuttle (16) drives the Piercer (3), upwards. ThePiercer Blade (28) travels through the lower foil, the Dose Pocket (43)and the upper foil. As the Shuttle (16) rotation continues the PiercerBlade (28) is retracted from the Dose Pocket (43).

With reference to FIGS. 5 and 6, the Piercer Blade (28) is a flat thinblade with Tang (25) features protruding out of the plane on eitherside. In one embodiment, each Tang (24) feature may extend down thevertical length of the blade towards the Piercer Carriage (23) so as tocreate a thicker central section of the Piercer Blade (28). The angledtip of the Piercer Blade (28) cuts a slit in the foil, at the centre ofthe dose pocket. As the Piercer Blade (28) moves upwards, the tangs foldthe foil into flaps which are pushed upwards and towards the long sideof the dose pocket.

The Piercer (3) component has Cam Follower Pegs (24) on opposite sides,which allow it to be driven vertically by the cam track of the Shuttle(16). The Piercer (3) is guided by a guide feature on the underside ofthe Chassis (1). With reference to FIG. 13, parallel cam track features(36, 37, and 38) on either side of the Shuttle interface with the CamFollower Pegs (24) on the Piercer Carriage (23). In other embodiments,the cam track features (36, 37, 38) may exist entirely on one side ofthe Shuttle (16) only or on one side and partially on the other side. Asthe Shuttle (16) rotates, following triggering, the Piercer Carriage CamFollower Pegs (24) encounter the Pierce Gate (47) and the Cam FollowersPegs (24) are driven up the Pierce Cam Track (36). This drives thePiercer Blade (28) through the dose pocket. As the Cam Followers Pegs(24) run down the retract cam track (37), the Piercer Blade (28) isretracted fully and the Cam Followers Pegs (24) pass through the ReturnGate (51), causing the Flexible Arms of the Return Gate Arm (51) todeflect. Once past this gate, the Cam Followers Pegs (24) cannot passback up along the Retract Track (38). The Cam Follower Pegs (24) passalong the Return Track (38) until the Shuttle (16) reaches the end ofits rotational travel.

The dry powder inhaler device according to present inventionincorporates a swirl chamber to deagglomerate the powder i.e., separatedrug particles from carrier particles. The following describes theairway and how air and powder are directed into the airway.

At the beginning of BAM Flap rotation, the BAM Flap will be positionedwithin a close fitting portion of the Flap chamber. Air flow into theSwirl Chamber will be highly restricted (to leaks only). When the BAMFlap has rotated through approximately 24 degrees, air can pass aroundthe end of the BAM Flap to the two inlet tubes leading to the SwirlChamber.

Initiation of free flow into and through the Swirl Chamber is intendedto be largely simultaneous with piercing of the dose pocket. Ideally,flow will be established through the two air inlet tubes just prior topiercing so that the dose pocket flow encounters the perpendicular airflow through the inlet. The tension in the Bistable Biasing Spring keepsthe BAM Flap in its open position throughout the inhalation. Evacuationof the dose pocket should be achieved within one full inhalation.Deagglomeration of the active fine particles from the lactose particlesis achieved by forces applied to the particles in the swirling air flowthrough the airway.

The airway consists of a swirl chamber with two tangential inlets; onecarrying clean air and the other carrying a mixture of air and entraineddose particles from the pierced dose carrier. These channels incorporatebends that facilitate the effective sealing of the airway with the BAMFlap chamber.

The Swirl Chamber includes a convergent section that increases the swirlvelocity of the air flowing through it and thereby increases themagnitude of inertial deagglomeration forces applied to the doseparticles. The convergent section also acts to increase the residencetime of agglomerates within the airway, which increases the time ofexposure to deagglomeration forces. The converging angle of theconvergent section (57) may play important role in the dose delivery.The preferred angle of convergent section is approximately 60° coneangle. In other embodiments, the preferred cone angle of convergentsection is from about 50° to about 70°.

The Swirl Chamber also contains an internal post or Central Post (55),which acts to increase the residence time of agglomerates by preventingdose particles exiting the airway during flow rate ramp-up at the startof a breath (before the swirling flow has been established).

The Swirl Attenuator/Mesh (54) (see FIG. 17(a)) at the exit of theairway is required to reduce the exit swirl velocity of the active fineparticles. This acts to prevent impaction of the active fine particlesin the mouth and throat, and encourages their delivery to the deep lung.The type of Swirl Attenuator/Mesh (54) may play important role in drugdelivery. The reverse angled mesh design may be preferred over crosshairmesh.

Priming of the indexing mechanism only occurs as the dose pocket ispierced. The Shuttle has a cam track profile that, as it moves, pushesagainst an Indexing Cam Follower (18) on the Indexing Arm (2) causingthe Indexing Arm (2) to rotate. The Pawl Arm (19) on the Indexing Arm(2) flexes and bumps over one of the drive teeth on the Dose Ring (13).The pawl arm tip is now in position to push against the Dose Ring drivetooth during indexing, during this movement the Dose Ring is preventedfrom rotating backwards by the positioning ratchet teeth on the Chassis.

When the Mouthpiece Cover is Closed:

The BAM is reset by the user closing the Mouthpiece Cover. As theMouthpiece Cover is rotated toward the closed position, the gear on theMouthpiece Cover axle drives the Idler Gear, which in turn drives thePriming Arm. The Drive Spring rotates (in its de-energised state) withthe Shuttle, which is rotated back to its start position by the flexibleclip on the Priming Arm which pushes against the drive lug on theShuttle. As the Priming Arm rotates, the Indexing Foot (29) on thePriming Arm drives the indexing cam follower (18) on Indexing Arm,causing the Indexing Arm to rotate about its axle. The tip of theflexible pawl arm pushes against the back of saw tooth on the Dose Ringand causes the Dose Ring to advance by one dose.

The Indexing Arm will only be moved by the Priming Arm if it haspreviously been primed by the action of the Shuttle rotating upon breathactuation. As the Dose Ring moves, the positioning ratchet arm on theChassis flexes and allows the Dose Ring tooth to pass. After thismovement the Dose Ring is prevented from rotating backwards by thepositioning ratchet teeth on the Chassis.

As the Shuttle rotates, the cam follower pegs on the Piercer Carriage,travel along the horizontal track, the cam track gate arms are flexedoutwards or upwards and the cam followers pass through this gate.

As the Shuttle rotates, the trigger arm is naturally biased towards thestop on the Chassis. When the notch in the trigger arm reaches the stopfeature, the trigger arm engages, preventing the Shuttle from rotatingclockwise (viewed from below) until it is re-primed and re-triggered.The Shuttle may only rotate a little further anticlockwise beforereaching a stop. To enable further free rotation of the Priming Arm,this component must be decoupled from the Shuttle.

The Flexible Clip (20) of the Priming Arm contacts a sloped ridge in theChassis that pushes the arm upwards, until it is out of contact with thedrive lug (30) of the Shuttle. Further rotation of the Priming Arm is nolonger coupled to the Shuttle. This is necessary in the design to allowthe Shuttle reset to complete before the Mouthpiece Cover approaches thefully closed position.

The BAM Flap itself is also reset to the closed position by the closureof the Mouthpiece Cover. A cam surface on the Priming Arm interfaceswith a cam-following surface on the Trigger so that as the Priming Armrotates, the Trigger (and therefore the BAM flap axle) is forced torotate. At a certain closure/opening angle close to ‘fully open’ the camsurface of the Priming Arm is concentric with the cam follower surfaceof the Trigger. This prevents the BAM Flap from rotating and thereforeprevents the device from inadvertently triggering during partialpriming.

Indexing only occurs when the user closes the mouthpiece and if the BAMhas been primed and actuated. This has the advantage of preventingwasted doses. The indexing mechanism moves empty dose receptacles awayfrom the opening position and aligns an unopened dose receptacle intothe opening position in preparation for the next patient dose.

The rotational position of the Dose Ring is maintained in storage by thepositioning ratchet teeth on the Chassis interfacing with the driveteeth on the Dose Ring. Once the BAM has fired, the Dose Ring will beindexed by one dose as the Mouthpiece Cover is rotated to a closedposition.

Once the last dose has been evacuated, the Dose Ring is indexed to its‘zero’ position as the Mouthpiece Cover is closed. When the Dose Ringreaches this zero position, it cannot be indexed further due to amissing ratchet tooth on the Dose Ring.

It will be possible for the user to prime the BAM Flap and pierce thezero position dose pockets if they choose to, however this would beconsidered misuse as in this position; zero will be displayed in thedose counter window.

As the Upper Clamshell is opened, the striker releases the mouldedsprung latch of the Airway which moves into a recess on the Dose Ringcorresponding to the zero position. This prevents the Dose-Ring frombeing rotated to any other position.

The number of doses remaining in the device is displayed in a windowthrough the Upper Clamshell. The numbers are printed on the lidding foilof the Dose Ring and can be viewed through the magnifying lens whichsits directly above the relevant number when the Upper Clamshell isclosed. When the 60th dose has been evacuated and the Mouthpiece Coverclosed, the number displayed will be “0”.

The dose ring used in breath-actuated dry powder inhaler of the presentinvention has been designed to have multiple cavities. It is alsonecessary that the material of construction be suitable since it needsto function as a Primary packaging component. The dose ring may be madefrom a plastic moulded/thermoformed component made from a polymer whichcan provide the needed water vapor transmission rate and oxygenpermeability specifications. The polymers used for this purpose may becycloolefin copolymer (COC) or polypropylene (PP) or polyvinyl chloride(PVC) or polyethylene (PE) or polycarbonate (PC) or polyvinylidenechloride (PVDC) or liquid crystal polymer (LCP) or Xenoy®′ which is ablend of semi-crystalline polyester (typically polybutyleneterephthalate (PBT) or polyethylene terephthalate (PET) andpolycarbonate (PC)) or Nylons or the like or combination thereof tocreate one or more layers during the moulding process. However many ofthese polymers while having a good barrier properties for oxygen do nothave a good barrier against moisture and vice versa. To overcome thislimitation, the cavities of the dose carrier can be formed/moulded froma high moisture barrier material like COC in the first layer andovermoulded with a good gas barrier material as the second layer.

The dose ring of the breath-actuated dry powder inhaler of the presentinvention has plurality of dose units. Any suitable number of the doseunits can be present on the dose ring depending on the size of the dosering. The dose ring may have dose units ranging from about 15 units toabout 120 units. In a preferred embodiment the dose carrier has 60 doseunits arranged side-by side along its circumference.

In an embodiment of the present invention, breath-actuated dry powderinhaler operates independently of the user's inhalational efforts. Inanother embodiment, the device would operate at inhalation rates aboveabout 40 liter/min and would give substantially constant doses even athigher inhalational rates. In this embodiment, the inhaler would onlyoperate at inhalation rates above about 40 liter/min and hencesub-inhalational efforts would not trigger the BAM mechanism anddispense any dose of the medicament. This would help to reduceaccidental double dosing by the patient. Also if the cap of the deviceis opened, but the user does not inhale, the BAM mechanism is nottriggered, thus avoiding wastage of the medicament.

The breath-actuated dry powder inhaler of the present invention issuitable for dispensing medicament, particularly for the treatment ofrespiratory disorders such as asthma and chronic obstructive pulmonarydisease (COPD) and for local action in the lungs. This breath-actuateddry powder inhaler can be used for delivery of medicament to the lungsfor systemic absorption. The inhalational device of the invention isused to administer medicament in the form of powder. The powdermedicament may be used as such or as a formulation with other excipientssuch as diluents for example, lactose, and mannitol. Appropriatemedicaments may thus be selected from, for example, analgesics, e.g.,codeine, dihydromorphine, ergotamine, fentanyl or morphine; anginalpreparations, e.g., diltiazem; antiallergics, e.g., cromoglycate (e.g.,the sodium salt), ketotifen or; antiinfectives e.g., cephalosporins,penicillins, streptomycin, sulphonamides, tetracyclines and pentamidine;antihistamines, e.g., methapyrilene; antiinflammatories, e.g.,fluticasone, flunisolide, budesonide, rofleponide, mometasone,ciclesonide, triamcinolone (e.g., as the acetonide) antitussives, e.g.,noscapine; bronchodilators, e.g., albuterol (e.g., as free base orsulphate), salmeterol (e.g., as xinafoate), ephedrine, adrenaline,fenoterol (e.g., as hydrobromide), formoterol (e.g., as fumarate),pirbuterol (e.g., as acetate), reproterol (e.g., as hydrochloride),diuretics, e g, amiloride; anticholinergics, e.g., ipratropium (e.g., asbromide), tiotropium, atropine or oxitropium; hormones, e.g. cortisone,hydrocortisone or prednisolone; xanthines, e g, aminophylline, cholinetheophyllinate, lysine theophyllinate or theophylline; therapeuticproteins and peptides, e.g., insulin or glucagon; vaccines, diagnostics,and gene therapies. It will be clear to a person skilled in the artthat, where appropriate, the medicaments may be used in the form ofsalts, (e.g., as alkali metal or amine salts or as acid addition salts)or as esters (e.g., lower alkyl esters) or as solvates (e.g., hydrates)to optimise the activity and/or stability of the medicament. Some of thepreferred medicaments are selected from albuterol, salmeterol,fluticasone propionate and beclomethasone dipropionate and salts orsolvates thereof, e.g., albuterol sulphate and the salmeterol xinafoate.Medicaments can also be delivered in combinations. Some of the preferredformulations containing combinations of active ingredients containsalbutamol (e.g., as the free base or the sulphate salt) or salmeterol(e. g., as the xinafoate salt) or formoterol (e.g., as the fumaratesalt) in combination with an antiinflammatory steroid such as abeclomethasone ester (e.g., the dipropionate) or a fluticasone ester(e.g., the propionate) or budesonide. A preferred combination is acombination of fluticasone propionate and salmeterol, or a salt thereof(particularly the xinafoate salt) or a combination of budesonide andformoterol (e.g. as the fumarate salt).

In another embodiment, breath-actuated dry powder inhaler of the presentinvention is capable of delivering from 1 mg to 50 mg of medication in asingle dose by making suitable changes in the device. The particle sizeof the carrier particles can range from about 10 μm to about 500 μm,preferably between 50 μm to μm. The particle size of the active agentcan vary from about 100 nm to 10 μm, preferably between 1 μm to 5 μm.The emitted dose from the device will be not less than 70%, preferablygreater than 90% of the total dose.

The term singular forms “a,” “an” and “the” include plural referencesunless the context clearly dictates otherwise.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and application of the presentinvention. It is therefore to be understood that numerous modificationsmay be made to the illustrative embodiments.

We claim: 1-16. (canceled)
 17. A method of indicating the inhalationdosage dispensed from a dry powder inhaler through emission of anaudible signal, the method comprising: (a) opening of a lever or amouthpiece cap of said inhaler to prime a breath activated mechanism(BAM) by rotation of the lever or the mouthpiece cover from asubstantially closed to a substantially open position; (b) successivelymoving a BAM flap from a substantially closed position to asubstantially open position, wherein a bistable biasing spring holds theBAM flap in the substantially closed position until the bistable biasingspring is overcome by a breath induced low pressure to allow opening ofthe BAM flap; and (c) wherein an audible signal is emitted upon movementof the BAM flap to said open position and wherein the audible signal isdirectly emitted by the movement of the bistable biasing spring,directly emitted by the movement of the BAM flap from a substantiallyclosed position to a substantially open position or is directly emittedby a combination of the movement of the BAM flap and the bistablebiasing spring. 18-19. (canceled)
 20. The method of claim 17, whereinthe dry powder inhaler comprises: (a) a body; (b) a dose-ringsubassembly comprising a dose ring and an airway including a swirlchamber and a mouthpiece, wherein the airway has airway inlets and anairway outlet, said airway forming a conduit for bypass air and drugladen air to mix and enter the swirl chamber, and wherein the dose ringis fully enclosed in the body of the dry powder inhaler during use andis capable of rotating through a segment of the airway, said dose ringcomprising a plurality of sealed longitudinal foil packets, with eachpacket containing dry powder comprising a dose of a drug, (c) the BAMcomprising a BAM flap movable from a substantially closed position to asubstantially open position and the bistable biasing spring holding theBAM flap in the substantially closed position, the BAM being primed byrotation of a mouthpiece cover from a substantially closed to asubstantially open position such that breath induced low pressureovercomes the bistable biasing spring to allow opening of the BAM flapwherein the bistable spring acts to move the BAM flap to the openposition, and (d) a piercer blade; wherein during the BAM flap travelfrom the closed to the open position, the movement of the BAM flapforces a latch retaining an energized dose opening mechanism to bedisengaged, thereby triggering dose opening by the piercer blade,wherein the dose opening mechanism is energized by the opening of themouthpiece cover and is held in a latched position until disengaged bymovement of the BAM flap and further wherein the piercer blade is ablade with tangs which cut a slit in the sealed foil packet of a dosepocket located on a dose ring such that the piercer blade moves througha lower foil, the dose pocket and an upper foil, and wherein the tangsfold the foils of the foil packet into flaps which are pushed upwardsand towards a long side of the dose pocket as the piercer moves upwards.21. The breath-actuated dry powder inhaler of claim 17, wherein the doseopening mechanism comprises a shuttle that rotates around an axis of thedry powder inhaler and furthermore incorporates a track that guides thepiercing element into and out of the sealed foil packet.
 22. Thebreath-actuated dry powder inhaler of claim 17, wherein inhalerincorporates a track that guides the piercing element into and out ofthe sealed foil packet, the track comprising at least three sections: ahorizontal track, a pierce track and a retract track with flexible gatesat interfaces that force the piercing element to follow a single routearound the track.
 23. The breath-actuated dry powder inhaler of claim17, which is reset by closing of the mouthpiece cover by a patient,wherein a priming component acting in a reverse direction to a primingaction engages with a trigger to close the BAM flap and moreover remainsengaged with the trigger to prevent the BAM flap from moving.
 24. Thebreath-actuated dry powder inhaler of claim 17, wherein during theresetting action, the priming component also acts on an indexingcomponent which drives the dose ring to rotate and positions a nextunopened dose pocket in line with the airway and the piercer ready forthe next inhalation.
 25. The breath actuated dry powder inhaler of claim17, wherein the swirl chamber comprises of tangential inlets, aconvergent section, an internal post and an attenuator.
 26. The breathactuated dry powder inhaler of claim 17, wherein said inhaler isreusable.
 27. The breath-actuated dry powder inhaler of claim 17,wherein the dose ring has dose units ranging from about 15 units toabout 120 units.
 28. The breath-actuated dry powder inhaler of claim 17,wherein the movement of the BAM flap to the open position results in apush of air to sweep through the dose pocket.
 29. The breath-actuateddry powder inhaler of claim 17, wherein, the said dose pocket is slitopen prior to the sweep of air through the dose pocket.
 30. Thebreath-actuated dry powder inhaler of claim 17, wherein the swirlchamber has a convergent section cone angle of about 50° to 70°.
 31. Thebreath-actuated dry powder inhaler of claim 17, wherein the swirlchamber has an attenuator design selected from the group consisting of areverse angled mesh design and a crosshair mesh design.
 32. Thebreath-actuated dry powder inhaler of claim 17, further comprising amagnifying lens on an upper clamshell of the body to display a number ofdoses remaining in the device.
 33. The breath-actuated dry powderinhaler of claim 17, wherein the piercer blade is of a planer shape, aspiral shape or a triangular shape.
 34. The breath-actuated dry powderinhaler of claim 17, wherein the piercer blade has at least one tang.